The present application claims priority upon Japanese Patent Application No. 2001-209840 filed on Jul. 10, 2001, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to an operation method of a storage, and particularly relates to a technique of providing an operation method of a storage which may promptly and easily enlarge a storage area of the storage in a case there is shortage in a remaining amount of the storage area of the storage, and which there is little waste for and may satisfy both a user and a provider of the storage.
2. Description of the Related Art
In accordance with development of IT techniques, a demand for a storage to contain a large amount of data is rapidly increasing. In particular, so-called data centers, performing operation of such as the recent ASP (Application Service Provider) related system and a Web system, are introduced with multiple disk array devices as a storage to store and manage a large amount of data which these systems handle.
As is well known, a disk array device has insertion slots for a plurality of disk units. When the disk array device is initially introduced, normally only the least number of necessary disk units required for the disk array device are installed, and the disk array device was operated in a form with the disk units appropriately increased when there was shortage of the storage area.
Here, the increase of the disk unit performed in the above operation form is normally performed in an arrangement where the user of the disk array device requests an enterpriser to increase the disk units and the enterpriser undertaking this work sends a service man to an established place of the disk array device, and the service man performs the increase of the disk unit. However, for example, when the popularity of a web site increases and a data amount rapidly increases, there is fear that the operation of the system may be interfered since the increase of the disk unit was not on time.
Thus, in order to promptly cope with the rapid increase of such data amount, there exists a disk array device comprising a function known as xe2x80x9con-demand functionxe2x80x9d. In this device, spare disk units are installed on the disk array device in advance, and when there is shortage of the remaining amount of the storage area of the disk array device, the spare disk units may be used by performing a simple operation to the disk array device (for example, refer to Japanese Patent Application 2000-295449). Note that, normally the spare disk units are temporarily provided for free for prompt coping, and the user who used the spare disk unit is to pay for the purchase price of the spare disk units afterwards.
Incidentally, there is a problem with the above on-demand function as follows. That is, the spare disk unit installed on the disk array device is not necessarily used, and accordingly the provider of the storage has a risk by installing the spare disk unit. Particularly the recent technical innovation of the disk unit is remarkable, and the spare disk unit, which is installed on the disk array device and has ended its term without being used and become obsolete, may not be easily used for other purposes and has a high possibility of becoming a poor stock.
Further, there are cases where the increase in the data amount is just transitory, and in such a case, even though the spare disk unit is purchased it may immediately become unnecessary, and the user is forced to purchase an expensive spare disk unit just for temporary use. Thus it is not a mechanism which necessarily satisfies the user. Further, when the installed spare disk units are all used up at an earlier time than initially expected, in the end, the enterpriser has to be contacted for an increase request, and the above mentioned conventional procedures have to be performed.
A main invention of the present invention to achieve the above object, is an operation method of a storage in which when the storage detects that a remaining amount of its own storage area is less than a predetermined value, a remote storage area provided by a remote storage connected to the storage via a predetermined communication means is utilized as the storage area.